I've just install Zimbra 5.0.9 under Ubuntu 8.04 and it's all working fine apart from accessing the address book from Thunderbird. I followed the wiki instructions to setup Thunderbird but searching the address book from Thunderbird returns no results.

If I ssh in to the server (called zimbra.mms or zimbra) and telnet to zimbra (or zimbra.mms) 389 I can successfully connect. From another computer if I try telnetting to zimbra 389 I get connection refused. I have disabled ufw and iptables is empty.

Is there some way I can get it to accept connections from other computers?